GENERAL AND INTERIOR DISTRIBUTION CV11 



One available set of our data may best be presented in tabular 

 form, for such use as the student may wish to make of them ; and to 

 this table we add, as an illustration of its use, only a few statements 

 concerning the more conspicuous ecological groups of our Illinois 

 fishes. 



By assorting the species according to the size of the ratios of fre- 

 quency of occurrence for each class of situations distinguished in this 

 table, we may separate those strongly preferring the given situa- 

 tion from those apparently avoiding it. In this way we learn that 

 the species occurring in our collections with disproportionate fre- 

 quency in the larger rivers of the state are the mud-cat (Leptops oli- 

 varis) , one of the river carp (carpio) , the toothed herring (Hiodon 

 tergisus) , and the sheepshead (Aplodinotus) , "among the larger fishes ; 

 and a small darter (Cottogaster shumardi) , the trout-perch {Percopsis 

 guttatus), and a minnow (Hybopsis dissimilis) among the smaller 

 fishes. 



The principal larger fishes of the smaller rivers make a much 

 longer list, comprising the hogsucker, two of the native carp (veli- 

 fer and difformis) ) a species of red-horse (aureolum) , the rock bass, 

 and the small-mouthed black bass; and the principal smaller 

 species are six darters (Etheostoma zonale, Hadropterus phoxocepha- 

 lus, H. aspro, Diplesion Uennioides, Etheostoma cwruleum, and Am- 

 mo cry pta pellucida), a stonecat (Noturus flavus), and Hybopsis 

 kentuckiensis , and four other minnows, all of the genus Notropis 

 (rubrifrons, gilberti, blennius, and cornutus) — their ratios running 

 from 70 per cent, for rubrifrons to 41 per cent, for cornutus. 



The species of our list which have from SO to 100 per cent, of 

 their representatives in creeks, as illustrated by our collections, in- 

 clude three sunfishes (the green sunfish, the round sunfish, and the 

 long-eared* sunfish), three suckers (the common sucker, the chub- 

 sucker, and the striped sucker), four darters, ten minnows, and the 

 brindled stonecat. 



The larger species found most abundantly in lakes, ponds, and 

 •other stagnant waters were the common bullhead, the buffaloes, the 

 yellow perch, the white bass, the yellow bass, the large-mouthed 

 black bass, and five sunfishes (both crappies, the warmouth,' the 

 pumpkinseed, and the bluegill) ; and the smaller kinds were the 

 smallest of our fishes (Microperca punctulata) , another darter (Bole- 

 ichthys fusiformis), two minnows {Notropis cayuga and N. heterodon), 

 the mud-minnow, and a killifish (Fundulus dispar). 



Turning next to the 62 species for which our data of preference or 

 avoidance of a muddy bottom are available, we find 7 species whose 



